scholarly journals Modified-atmosphere Packaging of Blueberry Fruit: Effect of Temperature on Package O2 and CO2

1992 ◽  
Vol 117 (3) ◽  
pp. 436-441 ◽  
Author(s):  
Randolph M. Beaudry ◽  
Arthur C. Cameron ◽  
Ahmad Shirazi ◽  
Diana L. Dostal-Lange
Keyword(s):  
Steady State ◽  
Partial Pressure ◽  
Modified Atmosphere Packaging ◽  
Vaccinium Corymbosum ◽  
Effect Of Temperature ◽  
Modified Atmosphere ◽  
Highbush Blueberry ◽  
Partial Pressures ◽  
Effects Of Temperature ◽  
Increasing Temperature

Highbush blueberry (Vaccinium corymbosum L. `Bluecrop') fruit sealed in low-density polyethylene packages were incubated at 0, 5, 10, 15, 20, or 25C until O2 and CO2 levels in the package reached a steady state. A range of steady-state O2 partial pressures (1 to 18 kPa) was created by placing a range of fruit weights within packages having a constant surface area and film thickness. The steady-state O2 partial pressure in packages containing the same weight of fruit decreased as temperature increased, indicating the respiratory rate rose more rapidly (i.e., had a greater sensitivity to temperature) than O2 transmission through the film. Steady-state O2 and CO2 partial pressures were used to calculate rates of O2 uptake. CO2 Production. and the respiratory quotient (RO). The effects of temperature and 02 partial pressure on O2 uptake and CO2 production and the RQ were characte∼zed. The steady-state O, partial pressure at which the fruit began to exhibit anaerobic CO2 production (the RQ breakpoint) increased with increasing temperature, which implies that blueberry fruit can be stored at lower O2 partial pressures when stored at lower temperatures.

scholarly journals Modified-atmosphere Packaging of Blueberry Fruit: Modeling Respiration and Package Oxygen Partial Pressures as a Function of Temperature

1994 ◽  
Vol 119 (3) ◽  
pp. 534-539 ◽  
Author(s):  
Arthur C. Cameron ◽  
Randolph M. Beaudry ◽  
Nigel H. Banks ◽  
Mark V. Yelanich
Keyword(s):  
Activation Energy ◽  
Mathematical Model ◽  
Steady State ◽  
Modified Atmosphere Packaging ◽  
Vaccinium Corymbosum ◽  
Published Data ◽  
Modified Atmosphere ◽  
Highbush Blueberry ◽  
Partial Pressures ◽  
Low Levels

A mathematical model was developed to characterize the interaction of fruit O2 uptake, steady-state O2 partial pressures in modified-atmosphere (MA) packages ([O2]pkg), and film permeability to O2 (Po2) from previously published data for highbush blueberry (Vaccinium corymbosum L. `Bluecrop') fruit held between 0 and 25C. O2 uptake in nonlimiting O2 (Ro2max,T) and the [O2]pkg at which O2 uptake was half-maximal (K½T) were both exponentially related to temperature. The activation energy of 02 uptake was less at lower [O2]pkg and temperature. The predicted activation energy for permeation of O2 through the film (\batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{E}_{\mathrm{a}}^{\mathrm{P_{\mathrm{o}_{2}}}}\) \end{document} kJ·mol-1) required to maintain close-to-optimum [O2]pkg across the range of temperatures between 0 and 25C was ≈ 60 kJ·mol-1. Packages in which diffusion was mediated through polypropylene or polyethylene would have values \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{E}_{\mathrm{a}}^{\mathrm{P_{\mathrm{o}_{2}}}}\) \end{document} of ≈ 50 and 40 kJ·mol-1, respectively, and would have correspondingly greater tendencies for [O2]pkg to decrease to excessively low levels with an increase in temperature. Packages that depend on pores for permeation would have an \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(\mathrm{E}_{\mathrm{a}}^{\mathrm{P_{\mathrm{o}_{2}}}}\) \end{document} of <5 kJ·mol-1. Our procedure predicted that, if allowed to attain steady-state conditions, packages with pores and optimized to 2 kPa O2 at 0C would become anaerobic with as little as a 5C increase in temperature. The results are discussed in relation to the risk of temperature abuse during handling and marketing of MA packaged fruit and strategies to avoid induction of anaerobiosis.

scholarly journals Modified-atmosphere Packaging of `Heritage' Red Raspberry Fruit: Respiratory Response to Reduced Oxygen, Enhanced Carbon Dioxide, and Temperature

1994 ◽  
Vol 119 (3) ◽  
pp. 540-545 ◽  
Author(s):  
Dennis W. Joles ◽  
Arthur C. Cameron ◽  
Ahmad Shirazi ◽  
Peter D. Petracek ◽  
Randolph M. Beaudry
Keyword(s):  
Steady State ◽  
Film Thickness ◽  
Partial Pressure ◽  
Surface Area ◽  
Modified Atmosphere Packaging ◽  
Fruit Weight ◽  
Rubus Idaeus ◽  
Modified Atmosphere ◽  
Modified Atmospheres ◽  
Partial Pressures

`Heritage' raspberries (Rubus idaeus L.) were sealed in low-density polyethylene packages and stored at 0, 10, and 20C during Fall 1990 and 1991 to study respiratory responses under modified atmospheres. A range of steady-state O2 and CO2 partial pressures were achieved by varying fruit weight in packages of a specific surface area and film thickness. Film permeability to O2 and CO2 was measured and combined with surface area and film thickness to estimate total package permeability. Rates of O2 uptake and CO2 production and respiratory quotient (RQ) were calculated using steady-state O2 and CO2 partial pressures, total package permeability, and fruit weight. The O2 uptake rate decreased with decreasing O2 partial pressure over the range of partial pressure studied. The Michaelis-Menten equation was used to model O2 uptake as a function of O2 partial pressure and temperature. The apparent Km(K½) remained constant (5.6 kPa O2 with temperature, while Q10 was estimated to be 1.9. RQ was modeled as a function of O2 partial pressure and temperature. Headspace ethanol increased at RQs >1.3 to 1.5. Based on RQ, ethanol production, and flavor, we recommend that raspberries be stored at O2 levels above 4 kPa at 0C, 6 kPa at 10C, and 8 kPa at 20C. Steady-state CO2 partial pressures of 3 to 17 kPa had little or no effect on O2 uptake or headspace ethanol partial pressures at 20C.

scholarly journals PREDICTING OPTIMUM PACKAGING CONDITIONS FOR MODIFIED ATMOSPHERE PACKAGES OF TOMATOES

HortScience ◽  
1992 ◽  
Vol 27 (11) ◽  
pp. 1161g-1162
Author(s):  
Sannai Gong ◽  
Kenneth A. Corey
Keyword(s):  
Steady State ◽  
Surface Area ◽  
Film Surface ◽  
Gas Diffusion ◽  
Fruit Weight ◽  
Effect Of Temperature ◽  
Modified Atmosphere ◽  
Wide Range ◽  
Input Variables ◽  
Increasing Temperature

Procedures for predicting optimum packaging conditions of modified atmosphere packages (MAP) of tomato (`Heinz 1370') were developed. The relationship between O2 consumption rate and O2 concn (RRo2) was determined using O2 depletion data collected by enclosing tomatoes in jars and sampling head space O2 concn over time. The fitted function was then used in conjunction with other input variables: (1) film permeability to O2 (PO2), (2) film surface area (A), and (3) fruit weight in packages (Wp) to develop the final predictive equation based on Fick's law of gas diffusion. Predictive power of the equation was tested by comparing the steady state O2 concn achieved experimentally with those predicted for a wide range of packaging conditions. Packaging conditions included film surface area, weight of fruit in packages, and O2 permeability of the film (0.0426 and 0.0620 ml/kg hr). Prediction curves showing steady state O2 concn vs. packaging ratio (A/Wp) closely resembled the best fit curves of data. The effect of temperature on steady state O2 concn in MA bags was also examined. Increasing temperature from 20°C to 28±2°C had little effect but decreasing temperature to 10°C led to higher in-package O2 concn. Results indicate that predictive equations can be used to select appropriate films and optimize packaging ratios to achieve desired steady state O2 concn for MAP of tomatoes.

scholarly journals Frequency Distribution of Steady-state Oxygen Partial Pressures in Modified-atmosphere Packages of Cut Broccoli

1994 ◽  
Vol 119 (3) ◽  
pp. 556-562 ◽  
Author(s):  
Panchanadham C. Talasila ◽  
Arthur C. Cameron ◽  
Dennis W. Joles
Keyword(s):  
Steady State ◽  
Partial Pressure ◽  
Coefficient Of Variation ◽  
Anaerobic Fermentation ◽  
Type Equation ◽  
Modified Atmosphere ◽  
Frequency Distributions ◽  
Partial Pressures ◽  
Ma Packaging ◽  
Product Variation

In one set of modified-atmosphere (MA) packages of cut broccoli (Brassica oleracea L., Italica Group), O2 partial pressures ranged from 1.2 to 3.6 kPa at 0C [88 packages, 0.00268-cm-thick low-density polyethylene (LDPE) film, 600-cm2 film area, 40±0.5 g cut broccoli], and in another set (94 packages, same film and area as before, 25±0.5 g cut broccoli) they ranged from 5.0 to 9.2 kPa. For characterizing O2 uptake as a function of O2 partial pressure and determining anaerobic fermentation induction point at 0C, a range of steady-state package O2 partial pressures was generated by placing different amounts of cut broccoli (10 to 160 g) in LDPE packages. Oxygen uptake was modeled using a Michaelis-Menten-type equation. The maximum rate of product O2 uptake when O2 partial pressure was nonlimiting and the package O2 partial pressure corresponding to half-maximum O2 uptake were estimated as 147±3 nmol·kg-1·s-1 and 0.26±0.025 kPa, respectively. Respiratory quotient and head space ethanol increased sharply below package O2 partial pressures of 0.15 kPa, indicating stimulation of fermentation within the packages. The frequency distributions of CO2 production rates were measured for 80 samples of 100 g each of cut broccoli at two O2 partial pressures (21.0 kPa and 1.3 kPa) using a flow-through method. The average coefficient of variation of the CO2 production rate was ≈5%. Frequency distributions of O2 partial pressures were modeled as a function of product-to-product variation in O2 uptake and package-to-package variation in film permeability using the estimated O2 uptake characteristics and coefficient of variation. The model was used to predict the target O2 partial pressures for the design of cut broccoli MA packages. It was predicted that the packages for cut broccoli at 0C should be designed for a target O2 partial pressure of 2.54 kPa to have actual package O2 partial pressures ≥1.0 kPa at 0.0001% probability level. Film specifications for MA packaging of cut broccoli at 0C were calculated based on the predicted target O2 partial pressures.

The effects of temperature and pH on the embryonic development of two species of Triturus (Caudata: Salamandridae)

2007 ◽  
Vol 28 (2) ◽  
pp. 295-300 ◽  
Author(s):  
Leonardo Vignoli ◽  
Marco Bologna ◽  
Manuela D'Amen
Keyword(s):  
Mortality Rate ◽  
Embryonic Development ◽  
Effect Of Temperature ◽  
Acidic Ph ◽  
Larval Life ◽  
Experimental Conditions ◽  
Rate Of Development ◽  
Constant Ph ◽  
Effects Of Temperature ◽  
Increasing Temperature

AbstractAmphibian populations are especially sensitive to aquatic parameters, in particular during embryonic and larval life. Our aim was to test for an effect of temperature (T = 13°C, 20°C and 25°C at constant pH = 7) and pH (pH = 5.5, 7 and 8.5 at constant T= 20°C) on embryos of two species of Triturus, T. carnifex carnifex and T. italicus (Amphibia, Salamandridae) using GLM procedure. Trend of embryogenesis processes, time to hatching and rate of development have a similar effect in both species in the used range of temperature and pH. Time to hatching decreased significantly with the increasing temperature. The pH experimental conditions had no effect on T. carnifex embryos survival, while the acidic pH condition raised the mortality rate in T. italicus, whose embryos should be more vulnerable than those of T. carnifex to acidification in nature.

Effect of temperature and modified atmosphere packaging on overall quality of fresh-cut bell peppers

LWT ◽  
2004 ◽  
Vol 37 (8) ◽  
pp. 817-826 ◽  
Author(s):  
G.A. González-Aguilar ◽  
J.F. Ayala-Zavala ◽  
S. Ruiz-Cruz ◽  
E. Acedo-Félix ◽  
M.E. Dı́az-Cinco
Keyword(s):  
Modified Atmosphere Packaging ◽  
Effect Of Temperature ◽  
Modified Atmosphere ◽  
Bell Peppers ◽  
Fresh Cut

scholarly journals Influence of Oxygen and Temperature on the Respiration Rate of Fresh-cut Cantaloupe and Implications for Modified Atmosphere Packaging

HortScience ◽  
2012 ◽  
Vol 47 (8) ◽  
pp. 1113-1116 ◽  
Author(s):  
M. Helena Gomes ◽  
Randolph M. Beaudry ◽  
Domingos P.F. Almeida
Keyword(s):  
Steady State ◽  
Shelf Life ◽  
Respiration Rate ◽  
Modified Atmosphere Packaging ◽  
Life Extension ◽  
Modified Atmosphere ◽  
Low Oxygen ◽  
Fundamental Information ◽  
Respiratory Behavior ◽  
Fresh Cut

The respiratory behavior of fresh-cut melon under modified atmosphere packaging at various temperatures was characterized to assess the potential for shelf life extension through low-oxygen and to generate information for the development of appropriate packaging conditions. Cantaloupe melon (Cucumis melo var. cantalupensis ‘Olympic Gold’) cubes were packaged and stored at 0, 5, 10, and 15 °C. Packages attained gas equilibrium after 5 days at 10 °C, 6 days at 5 °C, and 10 days at 0 °C. In cubes stored at 15 °C, decay started before steady-state gas levels were reached. Respiration rates were measured and respiratory quotient calculated once steady-state O2 and CO2 partial pressures were achieved inside the packages. O2 uptake increased with temperature and O2 partial pressure (pO2 pkg), according to a Michaelis-Menten kinetics described by = [( × pO2 pkg)/( + pO2 pkg)]. Respiratory parameters were modeled as an exponential function of temperature: = {[1.34 × 10−17 × e(0.131 × T) × pO2 pkg]/[1.15 × 10−24 × e(0.193 × T) + pO2 pkg]} (R2 = 0.95), Q10 = 3.7, and Ea = 84 kJ·mol−1. A good fit to the experimental data was also obtained considering as constant: RO2 = {[4.36 × 10−14 × e(0.102 × T) × pO2 pkg]/[0.358 + pO2 pkg]} (R2 = 0.93), Q10 = 2.8, and Ea = 66 kJ·mol−1. These results provide fundamental information to predict package permeability and steady-state pO2 pkg required to prevent anaerobic conditions and maximize shelf life of fresh-cut cantaloupe. The kinetics of respiration as a function of pO2 suggests that no significant reductions in respiration rate of fresh-cut cantaloupe can be achieved by lowering O2 levels.

scholarly journals MODIFIED ATMOSPHERE PACKAGING: TEMPERATURE DEPENDENCE OF THE RQ “BREAKPOINT”

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1139c-1139
Author(s):  
Randolph Beaudry ◽  
Arthur Cameron
Keyword(s):  
Carbon Dioxide ◽  
Steady State ◽  
Temperature Dependence ◽  
Oxygen Concentration ◽  
Modified Atmosphere Packaging ◽  
Oxygen Demand ◽  
Carbon Dioxide Production ◽  
Modified Atmosphere ◽  
Lower Oxygen ◽  
The Difference

The steady-state oxygen concentration at which blueberry fruit began to exhibit anaerobic carbon dioxide production. (i.e., the RQ breakpoint) was determined for fruit held at 0, 5, 10, 15, 20 and 25 C using a modified atmosphere packaging (MAP) system. As fruit temperature decreased, the RQ breakpoint occurred at lower oxygen concentrations. The decrease in the RQ breakpoint oxygen is thought to be due to a decreasing oxygen demand of the cooler fruit.The decrease in oxygen demand and concomitant decrease in oxygen flux would have resulted in a decrease in the difference in the oxygen concentrate on between the inside and outside of the fruit and thus decreased the minimum amount of oxygen tolerated. The implications on MAP strategies will be discussed.

scholarly journals The Anaerobic Compensation Point for Fresh-cut Watermelon and Implications for Postprocess Handling

HortScience ◽  
2004 ◽  
Vol 39 (3) ◽  
pp. 562-566 ◽  
Author(s):  
Jorge M. Fonseca ◽  
James W. Rushing ◽  
Robert F. Testin
Keyword(s):  
Shelf Life ◽  
Modified Atmosphere Packaging ◽  
Oxygen Depletion ◽  
Compensation Point ◽  
Modified Atmosphere ◽  
System Method ◽  
Limited Applicability ◽  
Fresh Cut ◽  
Elevated Rate ◽  
Increasing Temperature

The influence of temperature and O2 concentration on respiration and shelf life of fresh-cut watermelon was investigated. Product stored at selected temperatures from 1 to 30 °C showed increasing respiration and reduced shelf life with increasing temperature. Oxygen depletion and CO2 evolution were measured using a closed system method and rates of O2 consumption and CO2 production were computed. A mathematical model found to predict the CO2 production as function of temperature and O2 showed an elevated rate of CO2 production at about 14% O2 or lower. A modified atmosphere trial that compared product stored at 7 to 9 °C in air with product at either 14% or 8% O2 revealed increased respiration in the latter treatments, suggesting a relatively high anaerobic compensation point (ACP) at >14% O2. Our results suggest limited applicability of modified atmosphere packaging (MAP) for this product. Fresh-cut watermelon had extended shelf life and reduced respiration rate when stored at 1 to 3 °C and in >14% O2 atmospheres.

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